This invention is in the field of solar thermal power production. This invention relates generally to a solar trough and components thereof for collection, concentration, and conversion of solar energy to heat or electricity.
Solar power generation currently represents a small part of the total global electricity supply; however, there is an enormous potential for power generation worldwide using solar concentration techniques. Solar thermal power generation has advantages over solar power generation using photovoltaics including eliminating the need for large quantities of crystalline silicon for production of photovoltaic cells.
One technique for solar power generation utilizes arrays of reflective troughs for concentration of incident solar radiation, by reflection, onto receivers capable of efficiently converting the solar radiation to heat for subsequent utilization, for example power generation. Linear troughs having parabolic cross-sections are amongst the preferred shapes for solar troughs and various trough designs exist.
For example, U.S. Pat. No. 4,596,238 discloses a solar trough having a generally rectangular flexible sheet with a reflective surface. The sheet is formed into a concentrating shape by a pair of identical form members which are positioned at parallel edges of the flexible sheet and include a tensioning means positioned between the form members.
U.S. Pat. No. 4,611,575 also discloses a solar trough which utilizes parabolic ribs and cross members to form a rigid structure and reflective sheets formed of steel and having adhesively bonded reflective film thereon. The reflective sheets are formed into parabolic shapes by attachment to joining members attached to the parabolic ribs.
U.S. Pat. No. 5,964,216 discloses a trough-type parabolic concentrator which utilizes a reflector plate bent into a trough shape and a support structure made of a plurality of wooden frames. The wooden frames are joined together using screws to make a single parabolic segment and guide rails are attached to two adjacent parabolic segments to force the reflector plates to take a parabolic shape. The reflector plates are secured against slipping by wooden or metal stops placed at the outer ends of a segment.
U.S. Pat. No. 4,372,027 discloses a monocoque parabolic trough-type solar concentrator having reflective sheets attached to parabolic bows. Also disclosed is a roll-forming method for attaching a reflective laminate to the surface of the sheets of the monocoque trough.
One disadvantage of the solar troughs described above is that the reflective sheets are generally permanently attached to the supporting and/or shaping structure. In order to repair or replace the reflective sheets, the trough structures must undergo a significant amount of disassembly, increasing repair and assembly time and costs.